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1,493,717, R. A. WILSON WELL PLUG Filed May 6 192 15 plug.

Patented May 13, 1924.

u irEo STATES than? en reurerriee.

ROBERT WILSON, J5 DALLAS, TEXAS, ASS IGN OR- TO GUIBERSON CORPORATION, OF

DALLAS, TEXAS, A CORPORATION OF DELAWARE.

WELL PLUG.

Apiilication filed May 6, 1921. Serial no. 467,357.

To dZZ whom it m mom: I

Be it known that I ROBERT A. VILSON,

a citizen "of the United States, residing at Dallas, in the county of Dallas and State of Texas, have in'ventedcertain new and useful Improvements in Well Plugs, of which the following is a specification.

This invention relates to improvements in well I The invention has particularly to do with aplug or device for providing a water tight seal at the bottom of a well for the purpose of shutting ofi" flow of water from below and is commonly known as a bottomwater The invention i'sflan improvement on the clevi 'e' covered 165 Letters. a e No.'

1 330321), issuedto E. V. Crowell; February 10, 1920. The object of the invention is to provide an improved means for gripping and holding the core when the helical vanes are compressed and to enablethe use of a smooth core instead of the grooved core, which is illustrated in the. aforesaid patent. A further object is to simplify the construction and manufacture thedevice.

A cgins'truk'ztion designed to carry out the invention will be hereinafterdescribed together with other features of the invention.

The invention will be more readily understood from a reading of the following; specificaiton and by reference to the accompanyingdrawings, in which an example of the invention is shown wherein:

F 1 is an elevation of a plug construct'ed in accordance with my invention and in an expanded and unpacked condition, the well casing being shown in section,

is vertical sectional detail on an enlarged scale showing the bottom nipple and the improved gripping means, a

3 across sectional detailon the line 33 ofFig. 2, .7 i

4T3 an e urged vertical sectional view of the upper portion of heaeai'ce, and V Fig. 5 is an undereide' view 61' one of the grip ing slips; I As is well known, bottom water in a well is very troublesome and interferes with the production of oil by flooding the oil bearing sand. This water is generally under a high pressure and has great erosive power. This condition will become aggravated and more serious unless corrected.

In order toproperly seal the well to shut new and useful off this objectionable flow of water the bore of the well must be filled completely, with a substantial plug of plastic material capable or" hardening and held out against the wall of the well' under heavy lateral pressure, so that the bore spaces and variations in diameter of the latter will be thoroughly and closely held.

I In the drawings the numeral 10 designatesa core of steel or other material, upon the upper end of which is arranged a sleeve 11. The'sleeve has a -flange 12 into the center of hich the core is screw threaded. At its upper end the sleeve is connected to a liiie of pipe 13 byan ordinary collar 14:.

Helical vanes 15 have their upper ends "from the flange 12 to the collar 16 when in its extended position. Thecore 10 passes axially thru the vanes and telescopes into the nipple l7.

At its lower end the nipple is provided with a frusto-conical counter. bore 18 in which a plurality. of annular wedge shaped slips 19 are arranged. I have illustrated three of such slips, but it is tobe understood that thenumber may be varied. Each slip has its," inner vertical face provided with teeth and its outer face inclined at substantially the same angle as that of the counter bore, whereby said slips will freely slide in said counter hole. The outer corner 19 of each slip 19 is slightly reduced so as to obviate a point which would otherwise ride on thesurface of the counter bore and possibly score the same. The slips are supported in the counter bore by ,a retaining ring 20 which is screw threaded in the lower end of the nipple. The lower end of the nipple is externally screw threaded and inserted in the-upper end of the usual anchor pipe 21'. The core 10 slides thru the slips 19 and the and pr ects into the anchor 21.1 Tli e' piirt 11 61iti-tfit a head 1301 driving wardly in the counter bore 18, whereby the teeth will bite into the core and hold the same. It is obvious that when the flange 12, which carries the core 10, is moved toward the collar 16 the pitch of the screw formed by the vanes, will be lessened and the aggregate width from the outer edges of the vanes to the center of the core will be increased. Thus the outer edges of the vanes which are sharpened, are caused to bite into the wall of the well opening and to make .lateral pressure toward the said wall, thereby digging themselves in and positively gripping the wall of the well.

In use the plug arranged as shown in Fig. 1 is lowered into the well, and when in proper position the anchor pipe 21 which may be of suitable length, engages the bottom of the well. The plug is lowered below the casing and the helical vanes do not engage the side walls of the casing, but engage in the wall of the well hole. Tools are used to force the sleeve 11 downwardly toward the ring 20. The core 10 passes thru the slips 19 which act to prevent a reverse movement of said core and to hold the vanes in a compressed position. The vanes grip the well wall and after the device is in proper position, cement or other packing may be introduced, as much being added as may bedesired. In practice, while lowering the packing material it is advisable to mix ordinary fuel oil with the cement, but this is optional.

It will be understood that in the event there is a water bearing stratum below the productive oil stratum, which is separated from the oil stratum by an impervious stratum, and should the impervious stratum be penetrated by the drill, a bottom hole plug would be necessary to prevent the water from invading the oil sand. The anchor pipe 21 not only acts to properly position the plug, but being imbedded in the In ordinary practice the plug will be loaded with cement or packing material and placed in between the vanes before it is lowered, altho it is obvious that this may be done afterward. -However, the best results are obtained by lowering the packing with the plug. 1

In order to provide a means for holding a sealing medium in the helical vanes, a

' number of openings 22 are provided in the edges of the vanes and serve as anchorage for the sealing medium, and thru which wires (not shown) may be run if deslred to better hold the sealing medium in place, this being a common expedient, illustration is not believed necessary. The preferred form of sealing medium is oakum saturated with a thin cement mixture, wrung out about half dry and then tied in the helical vanes, however, itis to be expressly understood that any form of sealing medium may be used and the invention is not to be limited either to a sealing medium or any particular kind of medium. The plug after being loaded with sealing medium and attached to the anchor pipe of proper length, constitutes a complete plug in one direction and is given the power to automatically and promptly position itself-in a well and to seal or plug the holeat the point desired.

Particular stress is laid upon the use of the arcuate slips. These slips permit the use of a smooth core which is less expensive than a grooved core and provides-a more ample holding surface. Further the adjust ment of the core is not limited to the distance between grooves or recesses and it is not necessary to move the core a prescribed distance before the fastening means will i take hold. A further advantage is that it is not necessary to provide lateral holes thru the parts and there are no outside movable parts in connection with .the fastening means.

Various changes in the size and construction ofthe parts as well as modifications, may be made without departing from the spirit of the invention.

hat I claim, is:

In a well plug, a core having its lower engaging portion smooth, said core being provided at its upper end with a head, a tubular nipple slidably receiving the smooth engaging portion of the core, said-tubular nipple having a conicalbore at its lower end descreasing in diameter upwardly, the lateral wall of the conical bore being imperforate, the lower end of the tubular nipple being internally and externally threaded, ta pered gripping slips mounted in the conical bore and having their inner faces serrated to engage the smooth portion of the core, a removable ring receiving the core and having exterior screw threads to engage the interior screw threads of the tubular nipple, an anchor pipe engaging the exterior screw threads on the lower end of the tubular nipple, and helical vanes surrounding the core and attached'to said head and to the upper end of the tubular nipple.

In testimony whereof I aflix my signature.

ROBERT A; 'VVILSON. 

